MLB confirmed Polymarket as its official partner, granting the platform access to official data and league marks to support market settlement. In return, the league will gain greater visibility into trading activity expected to reach billions of dollars during the upcoming season.
The agreement includes a clause allowing MLB to terminate the partnership if courts determine that prediction markets violate state laws, according to a source familiar with the deal.
Separately, MLB Commissioner Rob Manfred and CFTC Chairman Michael Selig signed a confidential information-sharing agreement in Miami on Wednesday, establishing a framework for ongoing regulatory coordination.
Michael Selig, Chairman, said: "We're making sure that we have the right guardrails and integrity standards in place, and that's why we're partnering with MLB, because we've got to get this right."
Rob Manfred, Commissioner, said: "The fact that you have a federal regulatory scheme makes our life a lot easier as opposed to sports betting, where you're going state by state."
As part of the Polymarket deal, both parties will develop integrity safeguards to restrict markets deemed vulnerable to manipulation, including those involving individual pitches and in-game decisions.
Ari Borod said: "Integrity was at the foundation of this deal. It wasn't something that we figured out after the fact. It was at the forefront of the conversations."
The move places MLB alongside leagues such as the NHL, MLS and UFC, which have already explored partnerships in the prediction market space.
It also follows escalating legal tensions across the US, with Arizona filing criminal charges this week against Kalshi over allegations of operating an illegal gambling business.
Polymarket is currently operating on an invitation-only basis in the US and is preparing for a broader rollout ahead of the baseball season.
Unlike traditional sports betting, prediction markets are regulated at the federal level in the US through the CFTC
